Rehabilitation of the Dams at the Crescent and Vischer Ferry Hydroelectric Projects

by Andrew C. Sumner, New York Power Authority, Halfmoon, United States, Michael F. Nash, New York Power Authority, Halfmoon, United States, Thomas W. Haag, New York Power Authority, Halfmoon, United States,

This paper reviews the dam rehabilitation design and construction techniques used at the New York Power Authority's Crescent and Vischer Ferry Dams. The following are the major areas of rehabilitation discussed. Post tension anchor design, installation, and testing. Access and dewatering techniques. Concrete rehabilitation design, specification, and installation. Relocation of the Vischer Ferry regulating structure and pier nose addition. Flashboard design and installation. The dam rehabilitation work was completed in 1990, and its success is due to the value engineering applied by the Authority, the Engineer, and the Contractor.